The present invention relates to plumbing fixtures, and more particularly to drain assemblies used to control the flow of fluid through a drain opening of a basin, such as a sink or bath tub.
There a variety of mechanism for controlling drain passages in plumbing fixtures, for example, simple stops and plugs, drain plugs linked to a pull-up lever, and pop-up style drain plugs. Pop-up drain plugs are advantageous because the mechanism for opening and closing the drain is contained in a compact package set within or beneath the drain, without linkages, levers or other components that need to be concealed and routed through walls, underspaces and the like. Pop-up drain plugs are also advantageous because the push-button type movement required by the user for actuation is simple and intuitive. The user need to merely press down on the drain plug, such as by stepping on it or using one's hand, to alternately toggle between open and closed positions. Another advantage of pop-up drain plugs is that they typically can be installed from above the basin, rather than the often cramped, dark space beneath the basin.
An example of a conventional pop-up drain plug assembly is provided in U.S. Pat. No. 3,333,815. There a housing is threaded into the drain opening of the basin such that an enlarged flange protrudes above the drain opening. A push button above the drain opening has a seal that seats against the flange to close off flow through the drain. The push button is mounted to a spring-load cam arrangement that bolts to the housing and allows the seal to toggle between seated and unseated positions.
While the disclosed drain plug assembly provides the aforementioned advantages typical of such pop-up assemblies, it requires a large, protruding flange for the sealing surface, which can diminish the aesthetic appearance of the fixture. Also, the disclosed drain plug can allow objects that inadvertently pass through the drain opening to continue on to the drain plumbing, possibly irretrievably.
U.S. Pat. No. 6,880,179 addresses the latter problem by incorporating a strainer component that extends across the drain opening beneath the operating components of the assembly. The strainer thus can collect items which passed through the drain opening and are larger than the strainer openings. However, the user must reach down into the strainer passed the seal in order to retrieve the collected items. Moreover, the strainer has an enlarged flange against which the seal seats such that the aforementioned aesthetic problem remains.
U.S. Pat. No. 6,067,669 discloses a drain plug assembly that provides improved access to the contents of the strainer by permitting the operating components to be disassembled so that the strainer can be removed from the drain. However, the disclosed assembly is not of the pop-up type, and as mentioned, removal of the strainer requires disassembly and subsequent reassembly to return it to operable condition.